Esthetic Dentistry and Materials Science
Esthetic Dentistry and Materials Science tests material selection, shade communication and the sequencing of whitening, bonding and ceramic work.
Core rules
- Choose shade before the tooth dehydrates, in neutral daylight, and record value first, then chroma and hue, plus a cervical shade and any characterisation.
- Whitening with 10% carbamide peroxide in custom trays is effective for extrinsic and age-related staining; expect transient sensitivity. Bleaching does not change existing restorations, so plan replacement afterwards.
- Wait about two weeks after whitening before bonding composite, because residual peroxide inhibits polymerisation and the shade continues to change.
- Etch-and-rinse or self-etch bonding follows manufacturer instructions; do not over-dry dentine.
- Ceramic selection: lithium disilicate is etched with hydrofluoric acid and silanated; zirconia is not etchable and requires airborne-particle abrasion plus an MDP-containing primer.
- Consider flexural strength, fracture toughness, wear of the opposing tooth and thermal expansion when choosing a material.
Worked example
A patient with generalised fluorosis and existing anterior composites wants a brighter smile. Plan: shade assessment, whitening first with trays for two weeks, reassessment after two weeks, then replacement of composites on the whitened teeth with a shade matched to the new enamel. If veneers are chosen later, the preparation is kept in enamel and the incisal overlap is planned before cutting.
Traps
- Selecting a shade under the operatory light, then finding the crown is too bright.
- Etching zirconia, which produces no durable bond.
- Bonding immediately after whitening and getting a poor bond and colour mismatch.